Metastatic breast cancer is almost always incurable with standard chemotherapy, utilized either as single agents or in combination. Combination chemotherapy consisting of cyclophosphamide, doxorubicin (Adriamycin), and 5-Fluorouracil (CAF), or cyclophosphamide, methothrexate and 5-fluorouracil (CMF) are the most commonly employed regimens for the treatment of metastatic breast cancer, resulting in an overall objective response rate as high as 50-70%, complete response rate of approximately 10%, and a median survival of approx. 18-24 mos.